This invention relates to a nozzle assembly for a rotary drill bit and method of installation, and more particularly to such a nozzle assembly and method in which the nozzle assembly has a port oriented for discharging drilling fluid in a predetermined rotational position with respect to the longitudinal axis of the nozzle assembly.
Heretofore, much as shown in U.S. Pat. No. 4,533,005 dated Aug. 6, 1985, nozzle assemblies have been provided in which an inner nozzle member could be rotated relative to an outer securing ring or sleeve threaded within an internally threaded nozzle bore in the bit body for properly orienting the port in the nozzle member. However, the inner nozzle member for such externally threaded nozzle assemblies has rotated with the nozzle assembly during insertion or installation of the nozzle assembly within the nozzle bore. Then, after the initial installation, the nozzle member is rotated relative to the outer retaining sleeve or nut for proper orientation. In the event the nozzle member is not tightly secured, and particularly after long periods of use, the nozzle member may rotate and thus result in a disorientation of the deviated port.
In aforesaid U.S. Pat. No. 4,533,005 the nozzle member is held against rotation primarily by the compression of an adjacent O-ring. Such an arrangement, when the nozzle port is deviated at a relatively large angle and utilized with a high velocity drilling fluid may result in a disorientation of the nozzle port, particularly upon vibrations resulting from the drilling operation after prolonged periods of use and compression set of the O-ring.